Onan 5500 Generator surging

So my Onan Marquis Gold 5500w generator was giving me a hard time to start. Ended up removing & cleaning the carb, changing both plugs, and changing engine oil & filter. Got it running, except now it surges with or without a load. The throttle lever/choke arm jumps with each surge. No codes flash. Just want to get this thing to idle properly. Anyone have a similar problem? Any ideas? Thanks for any help.

After the ordeal i just went through with my gen, try running a can of Onan "C4" through it. Disconnect your fuel line from the carb, crank it over while you spray the C4 in, gen should run off of the C4. The gen will smoke and spit and spudder, have no fear it is normal. Make sure to remove your air filter before doing this. Run it with the C4 for a couple of seconds each time. reconnect your fuel line then finish off the can of C4
i did these steps to mine along with replacing the fuel pump and filters. gen runs like a champ now. I swear by this stuff. hope that helps

So my Onan Marquis Gold 5500w generator was giving me a hard time to start. Ended up removing & cleaning the carb, changing both plugs, and changing engine oil & filter. Got it running, except now it surges with or without a load. The throttle lever/choke arm jumps with each surge. No codes flash. Just want to get this thing to idle properly. Anyone have a similar problem? Any ideas? Thanks for any help.

it is probabley trying to look for a load....they surge when there is no load on them...turn some stuff on and it should stop....my guess

Well, I removed the mixture control solenoid under the float bowl today. It's not stuck, still has it's "plunging action". Next I'll probably try the C4, along with a new fuel filter and see if that helps.

with the Onan gen, you will have 2 fuel filters. there will be one mounted under your rig and one attached to the fuel pump itself. My fuel filter under the rig was clean as can be, the filter attached to the pump was clogged somethin fierce. just a lil FYI

I removed them both, too expensive for Onan parts. Went with a regular fram inline filter that I can see through to monitor. I feel your pain, been through many issues with mine due to sitting too long by the previous owner. I had to clean the carb jets, they were clogged and replaced the pump. Runs good now - knock on wood - and I make sure to start it at least every other weekend.

Onan's are very touchy. You need to start them up atleast once a month or just add an inline shut off valve and let the gen run empty. The gas evaporates and the varnish left over gums them up quickly.

Onan's are very touchy. You need to start them up atleast once a month or just add an inline shut off valve and let the gen run empty. The gas evaporates and the varnish left over gums them up quickly.

Exactly. I'm going to make it a habit to start it up around the 1st of the month, and run it for about an hour under load to try & prevent this from happening again.